Materials Data on K7(FeS2)5 by Materials Project

K7(FeS2)5 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of K–S bond distances ranging from 3.34–3.50 Å. In the second K1+ site, K1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of K–S bond distances ranging from 3.11–3.82 Å. In the third K1+ site, K1+ is bonded to six S2- atoms to form distorted KS6 octahedra that share corners with eight FeS4 tetrahedra, edges with two FeS4 tetrahedra, and faces with two equivalent KS6 octahedra. There are a spread of K–S bond distances ranging from 3.13–3.48 Å. In the fourth K1+ site, K1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of K–S bond distances ranging from 3.19–3.81 Å. There are three inequivalent Fe+2.60+ sites. In the first Fe+2.60+ site, Fe+2.60+ is bonded to four S2- atoms to form FeS4 tetrahedra that share corners with four equivalent KS6 octahedra, an edgeedge with one KS6 octahedra, and edges with two FeS4 tetrahedra. The corner-sharing octahedra tilt angles range from 17–67°. There are three shorter (2.26 Å) and one longer (2.29 Å) Fe–S bond lengths. In the second Fe+2.60+ site, Fe+2.60+ is bonded to four S2- atoms to form FeS4 tetrahedra that share corners with four equivalent KS6 octahedra and edges with two equivalent FeS4 tetrahedra. The corner-sharing octahedra tilt angles range from 23–47°. There are two shorter (2.24 Å) and two longer (2.26 Å) Fe–S bond lengths. In the third Fe+2.60+ site, Fe+2.60+ is bonded to four S2- atoms to form FeS4 tetrahedra that share corners with two equivalent KS6 octahedra, an edgeedge with one KS6 octahedra, and edges with two FeS4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–68°. There are a spread of Fe–S bond distances ranging from 2.23–2.31 Å. There are five inequivalent S2- sites. In the first S2- site, S2- is bonded in a 7-coordinate geometry to five K1+ and two equivalent Fe+2.60+ atoms. In the second S2- site, S2- is bonded in a 7-coordinate geometry to five K1+ and two Fe+2.60+ atoms. In the third S2- site, S2- is bonded in a 6-coordinate geometry to four K1+ and two Fe+2.60+ atoms. In the fourth S2- site, S2- is bonded in a 6-coordinate geometry to five K1+ and two Fe+2.60+ atoms. In the fifth S2- site, S2- is bonded in a 6-coordinate geometry to four K1+ and two Fe+2.60+ atoms.